1. Field of the Invention
The present invention relates in general to regenerative assisted braking, and more specifically, to a braking module for applying a remaining braking torque in addition to the regenerative braking torque.
2. Description of the Related Art
Electro-hydraulic braking systems with manually powered backup systems are used for actuating the vehicle brakes. The electro-hydraulic braking systems typically include three main hydraulic circuits. Two circuits include manual push through wherein isolation valves fluidically separate a manually powered master cylinder from the brake actuators. These isolation valves are ordinarily shut during normal braking mode to allow boost circuit controlled pressure to act on the hydraulic brake actuators of the manual push through circuits. As an operator of the vehicle depresses the brake pedal, the pressurized brake fluid is delivered to a brake simulator. Pressure transducers and pedal travel sensors are used to determine the braking level being commanded by the operator. Signals are sent to a control module, which in turn controls a motor/pump(s) and solenoid valve(s) in the first circuit to provide hydraulic braking fluid to act on the hydraulic actuators. In the event of a power failure or loss of hydraulic brake fluid of the first circuit, the isolation valves in the second and third circuits are opened to allow the operator to manually push through to actuate the front vehicle brake actuators during a fail-safe condition. Such a system is shown in U.S. Pat. No. 5,941,608 using multiple three-way proportional valves and pressure sensors. Each electronic device requires electrical power to energize and maintain the operation of each of the electrical devices. The use of electrical energy for energizing each electrical component within the electric-hydraulic braking system results in energy depletion. The more electrical devices within a system, the more the power consumption which is ultimately counter-productive to a system used in cooperation with regenerative braking being that the primary purpose of the regenerative braking is to recapture energy.